This disclosure relates to a brush seal assembly. More particularly, the disclosure relates to a method of securing bristles to a plate.
Brush seals are widely used to seal rotating structures. For example, the use of brush seals are prevalent in gas turbine engines. Typical brush seal manufacturing methods require numerous steps during which various components are welded to one another, which greatly impacts the manufacturing time and cost of the brush seal.
A brush seal typically includes at least three components: a bristle assembly or hoop and first and second plates arranged on either side of the bristle assembly. The plates and bristle assembly are joined to one another by various welds. One typical manufacturing process includes arranging the bristles in a fixture and securing a periphery of the bristles using a weld bead to provide the bristle assembly. The weld bead must then be machined to provide a smooth surface for subsequent welding operations. The machined bristle assembly is arranged between the plates and a weld bead is applied across the machined periphery and adjoining surfaces of the plates.
Typically, the components of the brush seal are tungsten inert gas (TIG) manually welded by a highly skilled welder. Automated laser welding, although suggested in the prior art, cannot be used because the machined surface of the bristle assembly must run true to the adjoining surface on the detail, which it does not. If adjoining surfaces are not true to one another, then porosity results in the weld when laser welding is employed, which renders the brush seal scrap. Moreover, since the orientation of the bristles is directional, the bristle assembly has been oriented and secured incorrectly relative to the plates, which renders the brush seal scrap.
What is needed is a brush seal manufacturing process that enables the use of automated laser welding and prevents improper orientation of the bristle assembly.